SeaMonkey 2.1 Beta 3 lets you enter Safe Mode from the Help menu, and you can permanently apply some of the Safe Mode settings if you so wish. When a plug-in crashes, you're now instantly presented with options, such as reloading the page. Built-in extensions such as ChatZilla, JavaScript debugger, DOM inspector, and DebugQA are now installed by default. SeaMonkey Sync has received an easier setup process, and Windows 7 jump lists are now supported. Also added are detection of outdated plug-ins, WebGL support, an optional search bar (including suggestions for search engines that support them), an engine manager for OpenSearch, and plug-ins now work in feeds shown in MailNews windows.

ChatZilla is working again, as are the JavaScript Debugger Venkman, as well as download progress display in the Windows 7 taskbar. Restoring large browser sessions has been improved, and you can even switch tabs by mouse scrolling.

This being a beta, the obvious warnings apply: stuff may break, bugs may show up everywhere, and generally speaking you probably shouldn't use this version as your daily driver -- at least not from the get-go, without having tested it for a while first.